PWM cooling fan(s) control using ECM

[GregWeld]

Originally Posted by carbuff

Andrew,

Question: when driving down the road normally, won't the fan spin due to airflow through the radiator? I'm curious how much more the motors spin the fans at 5% vs. what air passing through it would be?

That would take some math to figure out I assume, but I am curious.

Running down the road - the fan shouldn't be needed at all.

[andrewb70]

Originally Posted by GregWeld

Running down the road - the fan shouldn't be needed at all.

Precisely. See my comment above.

Andrew

[130fe]

Justin, do you have a link to the kit you listed?

[4wheels]

With some of the newer high output fans the vehicle speed based fan disable strategy isn't used anymore. If the cooling is enough that the fans aren't needed then they turn off due to temperature anyway.

Originally Posted by GregWeld

Running down the road - the fan shouldn't be needed at all.

[4wheels]

I am doing some testing of a stand alone PWM fan controller for a manufacturer. Since this is a stand alone system it reads a separate coolant temperature sensor and can be used on any vehicle (doesn't have to have PWM fan control strategy in the ECM).

One question that has come up in my testing is what is this other sensor reading for temperature since it isn't the same as the other temperature sensors in the cooling system (not the same sensor and may or may not be in the same location in comparison to engine, pump, thermostat, radiator etc.).

If you were a potential customer for this type of product, would an output of temperature from a fan controller be of interest? For example I would like to see it output temperature as a 0-5 volt signal that I could read with a data acquisition system or even just a simple volt meter. Might even be able to drive a gauge with this output (depends on the gauge type).

Any feedback/ideas?

Thanks.

[andrewb70]

Originally Posted by 4wheels

I am doing some testing of a stand alone PWM fan controller for a manufacturer. Since this is a stand alone system it reads a separate coolant temperature sensor and can be used on any vehicle (doesn't have to have PWM fan control strategy in the ECM).

One question that has come up in my testing is what is this other sensor reading for temperature since it isn't the same as the other temperature sensors in the cooling system (not the same sensor and may or may not be in the same location in comparison to engine, pump, thermostat, radiator etc.).

If you were a potential customer for this type of product, would an output of temperature from a fan controller be of interest? For example I would like to see it output temperature as a 0-5 volt signal that I could read with a data acquisition system or even just a simple volt meter. Might even be able to drive a gauge with this output (depends on the gauge type).

Any feedback/ideas?

Thanks.

If you are targeting users that may not have EFI, then I see a benefit to having a "temp out." As you said, this can be used to drive a gauge in the dash. I think most temp gauges use a thermister style sensor so the output would need to be resistance.

Andrew

[mikels]

Originally Posted by GregWeld

Running down the road - the fan shouldn't be needed at all.

Not completely true - if running the fan creates more negative pressure on backside of cooling system stack, running fan will increase cooling.

For example - when Mark switched Red Devil to 850W fan from 400W, it resulted in ~10 F reduction in coolant and oil temps (oil-to-water oil cooler in radiator) when running on track - with average speeds well above what you typically run on street.

Keep in mind this is a very thick (~5-6") cooling stack as well (A/C condenser, ICHE, radiator)

So ability to create more negative pressure on backside of cooling stack resulted in more airflow across coolers - and more heat transfer as a result.

Dave

[GregWeld]

Originally Posted by mikels

Not completely true - if running the fan creates more negative pressure on backside of cooling system stack, running fan will increase cooling.

For example - when Mark switched Red Devil to 850W fan from 400W, it resulted in ~10 F reduction in coolant and oil temps (oil-to-water oil cooler in radiator) when running on track - with average speeds well above what you typically run on street.

Keep in mind this is a very thick (~5-6") cooling stack as well (A/C condenser, ICHE, radiator)

So ability to create more negative pressure on backside of cooling stack resulted in more airflow across coolers - and more heat transfer as a result.

Dave

Good info Dave.... and Yes - I can certainly see in a racing situation, and with that much horsepower creating additional heat that needs to be dispersed. I was referring to a normal freeway cruising situation where even my Semi truck rarely engages the fan (air engaged fan of ginormous proportions).

[GregWeld]

I found this info in an article written about the 2016 Cadillac ATS-V:




The enemy of a performance car - beyond speed cameras and over-zealous highway police - is heat, and Cadillac has left nothing to chance there. Every grille and vent has a purpose, and in fact the engineers had to get creative to accommodate every heat-exchanger they wanted to install.

So, there are eight heat-exchangers in total, along with an 850W cooling fan. Each of the “grillettes” - the lower side grilles - has an intercooler, linked with the main cooler for the engine. The auto transmission alone gets two coolers, one in the traditional place behind the grille, and another mounted flat on the underside, near the front, the only spot Caddy had left.

[parsonsj]

Originally Posted by 4wheels

Any feedback/ideas?

Yes, it would be awesome for such a standalone controller to also support an AC pressure sensor. All the fan controllers I've seen just turn on the fans to a set speed (usually 100%) with a 12V input signal when the AC is turned on.